Push button switches are well known in the art and numerous examples thereof may be found in commerce. Typically, a push button switch is adapted to sequentially open and close an electrical circuit or to sequentially switch a common lead between two or more alternate circuits upon depression and release of its plunger.
A perceived problem with many types of push button switches is an instability caused when the plunger is partially actuated. If in the closed state, a less than full depression of the plunger may cause the switch to momentarily open. Upon release of the plunger, the switch returns to its original closed state. This problem is often found in automotive applications, where push button switches are mounted in cosmetic housings having an actuating button. During assembly, tolerance stacking of the mounting components may cause the housing button to hold the switch plunger in a partially actuated position. External vibration may then cause the switch to intermittently open when it is in the closed state. This problem has been overcome by ratchet tease free push button switches, such as taught by U.S. Pat. No. 5,226,529.
Another perceived problem with many push button switches, including ratchet tease free switches, is the snapping action of the switch as it changes from one state to another. This results in a popping sound, which may be amplified when the switch is mounted in an enclosed housing. In many applications a quiet, smooth actuation is preferred. Heart and bail push button switches provide the desired quiet and smooth actuation but, but are not known to be tease free.
There is, therefore, a need for a quiet, smooth acting, tease free push button switch.